function compareVersion(v1, v2) {
    v1 = v1.split(".");
    v2 = v2.split(".");
    var len = Math.max(v1.length, v2.length);
    while (v1.length < len) {
        v1.push("0");
    }
    while (v2.length < len) {
        v2.push("0");
    }
    for (var i = 0; i < len; i++) {
        var num1 = parseInt(v1[i]);
        var num2 = parseInt(v2[i]);
        if (num1 > num2) {
            return 1;
        } else if (num1 < num2) {
            return -1;
        }
    }
    return 0;
}
console.log(compareVersion("1.0", "1.0.0")); //相等：0 
console.log(compareVersion("2.0.1", "1.0.2")); //前面大：1
console.log(compareVersion("2.0.1", "3.3.1")); //后面大：-